PICO-56: 65C02/TMS9918A/AY-3-8910 on a Pi Pico

[visrealm]

To reduce the barrier for entry on my 6+ PCB HBC-56 project, I've created the PICO-56 emulating the entire thing on a Pi Pico (not a new idea by a long shot).

Emulating the following HBC-56 hardware

• 65C02 CPU
• 65C22 VIA
• TMS9918A VDP
• Dual AY-3-8910 PSGs
• Dual NES controller inputs
• PS/2 keyboard input
• 96KB Banked RAM/ROM

Making use of my various emulation libraries (and more):

• vrEmu6502- 6502/65C02 CPU emulation library (C99)
• vrEmu6522- 6522/65C22 VIA emulation library (C99)
• vrEmuTms9918 - TMS9918A/TMS9929A VDP emulation library (C99)

Includes a boot menu where ROMs can be loaded from SDCard.

Anyway, if you're interested in (yet another) Raspberry Pi Pico project emulating the above hardware, check it out.

https://github.com/visrealm/pico-56

[BigEd]

Nice! I think it's a great convenience to be able to update a ROM on an SD card - makes certain kinds of experiments and tinkering much easier.

[drogon]

Good approach.

What's the effective clock-speed of the 6502?

-Gordon

[visrealm]

drogon wrote:

What's the effective clock-speed of the 6502?

It runs the same as my HBC-56 at 3.6864MHz. It couldn't run much faster, even without me throttling it to that speed.

[okwatts]

I built one up from the kit and it all works nicely. I did test the basic using Gordon's ASCII Mandelbrot and by that timing it appears to be about 2.6 MHz (at least that's comparing to my other previous measurements). I'm looking forward to setting up the programming environment to see about other software (at least 6502 - C is not something I have done apart from 40 years ago as an intro.) Bare boards can be ordered if you can get the parts yourself otherwise the kit is quite reasonable.

[visrealm]

okwatts wrote:

I built one up from the kit and it all works nicely.

Nice one. Thanks for taking the chance to order the kit from a new seller. Appreciated.

I'll have to take another look at the benchmarks. They were taken before I added the 65C22 VIA emulation, so might be a factor, but wouldn't expect it to be that different.

If you could leave a rating/review on Tindie, I'd really appreciate it.

Cheers